From Brain Mapping to 3-D Printing Nanotechnology: A Journey of Curiosity

Boston Sensors Council Chapter and co-sponsored by IEEE Solid State Circuits Chapter and IEEE Electron Devices Chapter

To enable the understanding and repair of complex biological systems such as the brain, we are creating novel optical tools that enable molecular-resolution maps of large scale systems, as well as technologies for observing and controlling high-speed physiological dynamics in such systems. These technologies are also having unpredictable impacts, for example enabling new methods for making nanotechnology.

First, we have developed a method for imaging large 3-D specimens with nanoscale precision, by embedding them in a swellable polymer, homogenizing their mechanical properties, and exposing them to water – which causes them to expand isotropically manyfold. This method, which we call expansion microscopy (ExM), enables scalable, inexpensive diffraction-limited microscopes to do large-volume nanoscopy, in a multiplexed fashion – important, for example, for brain mapping.

Running this process in reverse – which we call imposion fabrication (ImpFab; Science (2018) 362(6420):1281-1285) enables the direct assembly of 3D nanomaterials consisting of metals, semiconductors, and biomolecules arranged in virtually any 3D geometry. This method enables 3-D printing of nanotechnology, because it can shrink swellable polymer-embedded objects until they are precisely brought into close proximity to each other, enabling for example metal nanowires to be made with ordinary biology lab equipment. We are now exploring how to inexpensively make objects such as large-scale optical metamaterials and other objects that are difficult, if not impossible, to make with older approaches.

Second, we have developed a set of genetically-encoded reagents, known as optogenetic tools, that when expressed in specific neurons, enable their electrical activities to be precisely driven or silenced in response to millisecond timescale pulses of light. We have also begun to develop noninvasive ways to electrically stimulate deep targets in the human brain, using the nonlinear properties of the brain to extract biologically relevant signals from applied high-frequency carrier electric fields applied from outside the brain.

Finally, we are developing novel reagents, such as fluorescent voltage indicators, and systems, such as novel microscope architectures, to enable the imaging of fast physiological processes in 3-D with millisecond precision. In this way we aim to enable the systematic mapping, control, and dynamical observation of complex biological systems like the brain. In addition, we are finding that we can have impact in other fields ranging from directed evolution, to 3-D printing of nanotechnology, and beyond.

Meeting Location: 125 Summer Street, Suite 2100 Brookline, MA 02215

For more information: For more information, contact Bruce Hecht at Bruce.Hecht@analog.com or Hari Chauhan at Hari.Chauhan@analog.com